For tumors harvested either at day 84 or when tumor volume reached 1.4 cc, enoxacin treatment following etoposide inhibited expression of a cancer stem cell marker CD133 in EWS34, and increased cleaved-caspase 3 which indicates the elevated apoptosis compared with that of the vehicle or etoposide-only groups (Fig. 4). Here, PROM1 is linked to cancer.